Adaptation refers to actions taken to lessen the impact of the (anticipated)
change in climate. Adaptive actions to reduce health impacts can be thought
of in terms of the classical categorisation of preventive measures in public
health (Last, 1995):

Primary prevention: actions taken to prevent the onset of disease
due to environmental disturbances, in an otherwise unaffected population (e.g.,
supply of bed nets to all members of a population at risk of exposure to malaria).

Secondary prevention: preventive actions taken in response to early
evidence of health impacts (e.g., strengthening disease surveillance and responding
adequately to disease outbreaks).

Tertiary prevention: health-care actions taken to lessen the morbidity
or mortality caused by the disease (e.g., improved diagnosis and treatment
of cases of malaria).

Primary prevention can be addressed at many levels - including, most radically,
the mitigation of the climate change process. In general, secondary and tertiary
prevention are less effective than primary prevention, although they are often
practically and politically easier to implement. In addition, there are both
ethical and social reasons to prefer primary preventive action wherever it is
feasible. In the long term, secondary and tertiary prevention measures usually
turn out to be more expensive than primary prevention.

A three-fold categorisation of strategies to protect population health is:
(i) administrative or legislative, (ii) technical/engineering, and (iii) personal
(behavioural) (Patz, 1996). Legislative or regulatory action can be taken by
government, requiring compliance by all, or by designated classes of, persons.
Alternatively, an adaptive action may be encouraged on a voluntary basis, via
advocacy, education or economic incentives. The former type of action would
normally be taken at international, national or community level; the latter
would range from international to individual levels. Adaptation options can
operate at different spatial levels, from local to global. Some of the options
are of a structural and general kind, facilitating and maximising preventive
impacts. Other options are of a more specific kind, entailing procedures, technologies
or behavioural changes. Table 14.4. shows the major adaptation options for reducing
the health impacts of climate change, and the major considerations that bear
upon their effectiveness.

Monitoring and surveillance of environmental, biological and health status

++

+++

+

++

Integrated environmental management

L

+

++

+

++

Urban design (including transport systems)

L

+

+

++

++

Housing, sanitation, water quality

L

+

+

+

+

Specific technologies (e.g., air conditioning)

L

+

+++

+

+

Public education

L

+++

+++

+

+

* G = Global, N = National, L = Local.

Actions to reduce the health impacts of climate change are basically
public policy response options and are, therefore, in the latter system. The
ultimate goal of these interventions is the reduction, with the least cost,
of diseases, injuries, disabilities, suffering and death. There is little
quantitative information about how humans adapt either biologically or culturally
to climate change. Most assessments of the health impacts of climate change
have therefore not addressed adaptation explicitly and quantitatively. However,
some assessments of the impacts of thermal stress have modelled, by extrapolation
from short-term observations, the effect of longer-term acclimatisation at
the population level (e.g., Kalkstein and Greene, 1997). The most effective
way to reduce potential health impacts will be through adaptation technologies
that reduce the overall level of population vulnerability. The potential impacts
of climate change on food and water are not seen as the responsibility of
public health agencies.